package cn.edu.scau.cmi.liquan.exercise5;

public class Circle {
      double radius,area;
      Circle(){
      }
      Circle(double r){
    	  radius=r;
      }
      void setRadius(double r) {
    	  if(r>0) {
    		  radius=r;
    	  }
      }
      double getRadius() {
    	  return  radius;
      }
      double getArea() {
    	  area=3.14*radius*radius;
    	  return  area;
      }
}
